Chronic kidney disease (CKD) is one of the greatest risk factors for cardiovascular disease (CVD). The contribution of CKD to CVD mortality is not well understood in very elderly patients. Our study examined whether CKD might be a risk factor for total and CVD mortality in very elderly Japanese individuals. A total of 621 participants were enrolled, all of whom were 80 years old. The subjects were divided on the basis of the presence (CKD(+) group, n=280) or absence (CKD(-) group, n=341) of CKD. CKD was defined by as an estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m(2). The eGFR of the CKD(+) and CKD(-) groups was 49.7+/-8.5 and 70.9+/-9.5 mL/min/1.73 m(2), respectively. During the 4-year study period, 87 individuals died, and 25 of those deaths were due to CVD. A Cox multivariate regression analysis revealed no association between total mortality and CKD (relative risk [RR] 1.17, confidence interval [CI] 0.75-1.82, p=0.50). However, the CVD mortality was significantly increased in the CKD(+) group (RR 4.60, CI 1.69-12.52, p=0.003). CKD significantly increased the CVD mortality in subjects who were not taking antihypertensive medication (RR 5.15, CI 1.04-25.50, p=0.04). Our results suggest that CKD increases the risk of CVD mortality in very elderly individuals. It is not only important to prevent progression toward CKD in patients who do not suffer from CKD, but also critical to manage the risk factors for CVD in patients with CKD, despite their advanced age. (Hypertens Res 2008; 31: 2053-2058).